1. Field of Invention
This invention relates to gas springs modified to operate as an electrical connection, and particularly to gas spring arrangements including such a gas spring.
2. The Prior Art
A gas spring, as the term is most commonly understood, includes a cylinder whose cavity encloses a body of gas under high pressure, and a piston rod or plunger movably sealed in an end wall of the cylinder for axial movement into and out of the cavity. The gas tends to expel the piston rod from the cavity and resiliently opposes inward piston rod movement under the weight of a sprung mass.
It is known from German published applications Nos. 2,332,791; 2,421,007; and 2,614,927, as well as from German utility model No. 7,304,750 and British Pat. No. 1,282,568 that a gas spring, when interposed between a movable closure and a fixed body portion of a motorcar, may be employed for controlling movement of the closure about a horizontal axis, and may simultaneously provide a conductive path between a source of electric current on the fixed body portion, and an electrically operated device mounted on the closure, such as a lamp, a window heater, or a window wiper.
The known gas spring arrangements can provide only a single electric circuit, and there exists a need in many instances for multiple, independent circuits separately connecting several current-consuming devices on a closure member with a current source on the fixed body portion through respective switches.